Security, and particularly vehicle security, has long been a concern for users and owners of vehicles. With the development of electronic and processor-based vehicle entry and ignition systems, conventional vehicle security systems have provided adequate, albeit minimal, protection. In the last decade, conventional “key and lock” systems have been augmented with remote access in which users are able to open their vehicles remotely by pressing a button on their key fobs. In these systems, the authorization to drive is mainly enforced by a physical key and lock system. Physical keys may contain embedded immobilizer chips to prevent key copying. Recently, car manufacturers have introduced Passive Keyless Entry and Start (PKES) systems (sometimes referred to in the art as “smart key” systems) that allow users to open and start their cars without requiring a physical key. This feature is very convenient for the users since they don't have to search for their keys when approaching or preparing to start the car.
PKES systems are typically configured to automatically unlock a vehicle when the user carrying the key approaches the vehicle, and locks the vehicle when the user moves away from the vehicle. The system is referred to as “passive” as it does not require any action from the user. The communication between the key and car is characterized by a magnetically coupled radio frequency signal. In this system, the vehicle determines that the key is in the close proximity when it is within the vehicle's communication range. A PKES key typically relies on a low-frequency radio-frequency identification (LF RFID) tag that provides short range communication (e.g., within 1-2 m in active, and a few centimeters in passive mode) and a ultra-high frequency (UHF) transceiver for longer range communication (within 10 to 100 m). This configuration is used to detect if the key fob is within regions inside and outside of the vehicle. For remote distance regions (e.g., up to 100 m), only locking/opening the vehicle by pushing a button on the key fob is allowed. For close proximity regions (e.g., 1-2 m from the door handle), opening/closing the vehicle, by using the door handle, is allowed. For regions inside the vehicle, starting the engine is allowed.
One problem with such conventional systems is that the PKES systems have been shown to be vulnerable to hacking. For example, the relay attack is a well-known attack against communications systems, where messages are relayed from one location to another in order to make one entity appear closer to the other. In the area of RFID and vehicle systems, a relay attack may comprise an attack on the physical layer by relaying LF signals from the vehicle over an RF link comprising an emitter and receiver. The emitter captures the LF signal and up-converts it to 2.5 GHz. The obtained 2.5 GHz signal is then amplified and transmitted over the air. The receiver part of the link receives this signal and down-converts it to obtain the original LF signal. This LF signal is then amplified again and sent to a loop LF antenna which reproduces the signal that was emitted by the car, allowing the opening and starting the engine of the car.
While certain solutions, such as adding various level of encryption to the signal have been proposed, these solutions are overly complex for implementation within a vehicle system, and require continuous updating to ensure that encryption keys retain their integrity and are properly matched. Furthermore, conventional security and authentication techniques do not adequately take into consideration the behavioral patterns or schedules of users with respect to their vehicles. What is needed is a system that provides vehicle authentication in an effective and simplified manner that also considers behavioral and/or scheduling characteristics of a vehicle's user.